Apparatus for printing cinematographic films.



I P. 0. BREWSTER, APPARATUS FOR PRINTING CINEMATOGRAPHIC FILMS.

APPLICATION FILED APR.22, I915.

1,267,844. Patented May 28, 1918.

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P. D. BREWSTER.

APPARATUS FOR PRINTING CINEMATOGRAPHIC FILMS.

APPLICATION FILED APR.22,1915.

1,267,844. Patented May 28,1918.

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EYM anemia UNITED STATES PATENT PERCY D. BREWSTER, OF EAST ORANGE, NEW JERSEY.

APPARATUS FOR PRINTING CINEMATOGRAPHIC FILMS.

- Application filed April 22, 1915.

To all whom it may concern:

Be it known that I, PERCY D. BREWSTER, a citizen of the United States, residing at East Orange, county of Essex, and State of New Jersey, have invented certain new and from an opaque negative having imageson both sides, and its chief object is to provide an effective and convenient apparatus for the purpose. To this and other ends the invention consists in the novel features of construction and combinations. of parts hereinafter described.

One form of the invention is illustrated in the accompanying drawing, in which- Figures 1 and2 are edgewise views of different types of negative film capable of use in the present invention, and Fig. 3 isa similar view of a suitable positive film, these three views being of course much exaggerated in size. Fig. 4 is a sectional plan view of the printing apparatus, or printer, and Fig. 5 is a detail view, on a smaller scale, of one of the shutters used in the printer.

Figs. 6 and 7 are detail sections on lines 6 and 7 respectively, of Fig. 4:.

The negative for which the present printer is primarily designed is opaque or semiopaque, with negative images on both sides,

it being understood that in color cinematography-the iniageson one side are prouduced by light of one color or group of colors of the spectrum and that those on the other side are produced'by light of another color or group of colors. These images may be on a highly reflective support, such as white celluloid or baryta paper. Fig. 1 illustrates such a film, 1 being the white celluloid'support, and 2 and 3 the two coatings bearing the images. In Fig. 2 the celluloid base 4 may be transparent, in which case it is provided with one or more opaque reflective substrate. 5 under the coatings 6, 7. Or the negatives may be on transparent celluloid without opaque substrata or layers. In this case fixation after development is omitted, so that the white or yellowishwhite tone of the unreduoed silver bromid in the emulsion will afi'ord a suitably contras- Speciflcation of Letters Patent.

Patented May 28, 1918.

Serial No. 23,025.

tive ground for the reduced silver of the images. Negative of these types and a simple method of making the same are described in my copending application Ser. No. 13,595, filed March 11, 1915. color not sufliciently actinic to affect ordinary emulsions on the positive film to the desired degree the latter can be coated with emulsions sensitized for that color.

In printing from an opaque negative by If the ground is of a means-of the present invention the negative film 1, Fig. 4:, is fed intermittently throu h the film gate 8, as by any convenient mec anism, not shown. The printing light, from shaded lamps 9, 9, on opposite sides of the film gate, is reflected from the images on the film to two suitably inclined mirrors or reflectors 12, 26, which reflect the rays to the lenses 10, 25, in the wall of the lighttight housing 48. The lenses project the rays upon two inclined reflectors 16, 30, which in turn reflect the rays to the two sensitive emulsions 23, 2 1 of the positive film 22, forming positive images thereon. The positive film is fed intermittently through its film gate 49 (preferably in the same plane as or at least parallel to the negative film) by any convenient and suitable mechanism, not shown, timed to operate in harmony with the negative-feeding mechanism so both films will be at rest during the exposure. Filmfeeding mechanisms being so well known, to show any particular type would merely complicate the drawings without serving any useful purpose. Suflice it to say that if the mechanism is of the sprocket type, controlled by a Geneva stop, the latter can be connected with both sets of sprockets so as to control both. The exposure of the two sides of the pos1- tive film 1s controlled by two revolving shutters on a shaft 40 mounted in a bearing 41 and rotated (by any suitable means, not

shown) in harmony with the film-feedin devices. The shutters are each com osed o sectors, 3637, 38-39, an larly a justable on the shaft 40. The width of the openings in the shutters can thus be varied to regulate the duration of exposure of each side of the positive film independently "at the other, aswill be readily understood. Preferably one sector or blade of each shutter is fixed to the shaft. Either blade of each pair is provided with a series of apertures 50 and the other with a lug or pin 51 to snap into one of the apertures when the adjustable blade has been shifted to the desired position. One or both blades are made of flexible material, as sheet steel, so that the two can be readily sprung apart to disengage the lug from the aperture when desired. This capability of varying the exposures of the two sides of the positive film. independently, as by varying the ratio between the open and closed portions of each shutter, is a highly advantageous feature, as it affords easy compensation for faults in the negative, for instance greater density of the ,images on one side of the negative film than on the other, for difference 1n the speed of the two positive emulsions, for inequality of illumination on the two sides of the negative, etc. It will, be understood that while the two films are in motion the positive film is not reached by the light, being protected, in the present machine, by the ing shifted by means of the adjusting screws 44, 47. The end portions of the housing 48, which inclose the reflectors 16, 30, are connected to the body of the housing to permit removal for access to the reflectors or to permit said end-portions to be attached to and to move with the slidable reflector-bases.

Shifting the positive images vertically and horizontally to bring them into proper registry is efl'ected by turning the reflectors 16, 30 on horizontal and the reflectors 12, 26 on vertical axes. For this purpose the carriers 14, 27, on which the reflectors 12, 26 are fixed, are mounted on vertical pins 13,

28, capable of rotary movement in the baseplates 45, and can be shifted by the screws 14 26, working in ln s 15, 29 on the baseplates, The carriers 1 31, holding the reflectors 16, 30, are mounted onhorizontal pins 19, 32, journaled in lugs 18, 33 on the plates 45, and are shifted by means of capstan screws 20, 35, working between the baseplates and the stops 21, 34. The lenses 10 are threaded in the housing wall, so that any necessary axial adjustment can be eflected by rotating them. I

If for any reason the images on the negative film are not in proper registry, the images projected upon the positive film can nevertheless be registered, by compensating ad ustment of the reflectors, as will be readly understood. If it is desired to make the image on one side of the positive film larger than the other, to compensate for the an gularity of the raystransmitted by the condcnsers of a projecting apparatus (as explained in my copending applications Ser. Nos. 815,153, 843,351, 855,943 and 870,752) one of the printing lenses can be of greater focal length than the other and be set at a slightly less distance (measured on its axial ray) from the negative; or a piece of glass of suitable thickness, with plane parallel sides, can be interposed between one lens and the negative film, and the lens adjusted to secure the desired sharpness of focus on the positive film.

Referring to Fig. 4, it will be seen that, in

general, the image on side 2 of the negative film should not be impressed upon side 24 of the'positive, or vice versa, as that Would impair the color separation of the two images, but it may happen if the negative film isnot sufliciently opaque. The same result would be caused by transmission of light through the transparent celluloid 22 of the positive film. The difiiculty can, however, be obviated in various ways. For instance, the printing lights may be of different colors and the positive emulsions non-sensitive to colors other than those by which they should be aflected. Thus the lights 9 may be green and lights 9 red, in which case positive emulsions 23 would be sensitized (say with acridin orange) for green and emulsion 24 sensitized (say with pinacyanol) for red. Another method of obviating the difliculty with respect to transparency of the positive film is to give the latter full exposure and then short development with a high factor developer, for example metol, so that only the outer surface of the emulsion is acted on. Then any latent printed-through image, which would necessarily be near the celluloid, would not be developed and would be cleared in the fixing bath. A method of avoiding the effects of imperfect opacity of the ne ative film is to set the shutters 36-37,

4 3839 so as to work in alternation, and to ilhrminate the two sides of the negative al ternately.

After the positive film is developed and fixed theimages on the two sides are colored, or dyed in colors which are in general complementary to the colors of the light by which the corresponding negative images were produced. Thus if the negative images were produced one by green and the other by red light, the corresponding positive images would be colored red and green respectively. The dyeing or coloring can be effected by the well known Traube method or by changing the silver of the images into a transparent condition by treatment with iodin, after which the fihn is treated with dyes of the desired colors, asfor example a green dye on one side and a red dye on the other.

The printing apparatus described above is essentially like that illustrated in my prior application Ser. No. 870,754, filed Nov. 7,

1914. Both are capable of use with either opaque or transparent negatives. The lighttight housing 48 is shown inclosing the ositive side of the apparatus, as this enab es it to be used in an ordinary lighted room. If the negative side is inclosed and the other open, the apparatus must be used in a dark room or in a light to which the positive emulsions are not sensitive.

It is to be understood that the invention is not limited to the apparatus herein specifically illustrated and described, but can be embodied in other forms without departure from its spirit.

I claim:

1. In a photographic printer for projecting suitably registered images from a negatived filmupon opposite sides of a positive film, in combination, negative and positive film gates arranged to support two independent films, means to illuminate a film in the negative film gate, and optical means for projecting images from both sides of the illuminated film upon opposite sides of the other film.

2. In a photographic printer for projecting suitably registered images from a negative film upon opposite sides of a positive film, in combination, negative and positive film gates arranged to support two independent films, means to illuminate the sides of a film in the negative film gate, reflectors arranged to reflect light rays from the two sides of the illuminated film in the negative film gate to the two sidesof a film in the positive film gate, and projecting lenses in the paths of said rays.

3. In a photographic printer for projecting suitably registered images from a negative film upon opposite sides of a positive film, in combination, negative and positive film gates arranged to support films in the same plane side by side, means to illuminate both sides of a film in the negative film gate, a housing inclosing the positive film gate, and optical means for projecting through an adjacent wall of the housing and upon the two sides of a film in the positive film gate images from the two sides of a film in the negative film gate.

4:. In a photographic printer for projecting suitably registered images from a negative film upon opposite sides of a positive film, in combination, negative and positive film gates arranged to support films side by side in the same plane, means for illuminating both sides of a film in the negative film gate, optical means, including reflectors and lenses, for projecting upon the two sides of i a film in the positive film gate images from the two sides of a film in the negative film gate, and means for protecting the film in the positive film gate from photographically active light rays save such as pass through said lenses.

5. In a photographic printer for project ing suitably registered images from a negative film upon opposite sides of a positive film, in combination, negative and positive film gates arranged to support two independent films, optical means for projecting upon the two sides of a film in the positive film gate images from opposite sides of a film in the negative film gate, and eXposureshutters in the paths of the light rays from means to project images from opposite sides of the negative film to opposite sides of the positive film, for illuminating a film in the negative film gate, and a housing supporting said lenses and serving to permit only photographically active light transmitted by the lenses to reach the positive film gate.

7. In a photographic printer for projecting suitably registered images from a negtive film upon opposite sides of a positive film, in combination, negative and positive film gates arranged to support two inde pendent films, optical devices for projecting upon a film in the positive film gate images from the opposite sides of a film 1n the nega tive film gate, and means for adjusting a plurality of said devices to focus the aforesaid images.

8. In a photographic printer for projecting suitably registered images from a negative film upon opposite sides of a posltlve film, in combination, negative and positive film gates to support two independent films, optical devices for projecting upon opposite sides of a film in the positive film gate images from the opposite sides of a film in the negative film gate, said devices including reflectors and projectin lenses, means for ad justing a plurality 0 said devices to focus the aforesaid images, and means for shifting the reflectors to bring said images into registry with each other.

9. In a photographic printer for projecting suitably registered ima es from a negative film upon opposite si es of a positive film, in combination, negative and positive film gates to support two independent films, projecting lenses on op osite sides of the film gates, a pair of re ectors arranged on opposite sides of the negative film gate to receive light from a negative therein and reflect the same'into the res ective lenses, a pair of reflectors arrange on opposite sides of the positive film gate to receive light from the respective lenses and reflect the same to opposite sides of a film in the positive film gate, means for turning the reflectors of one pair in one plane, and means for turning the reflectors of the other pair in a plane at right angles to the first-named plane.

10. In a photographic printer for projecting suitably registered images from a negative film upon opposite sides of a positive film, in combination, negative and positive film gates arranged to'support two independent films, means for illuminating a film in the negative film gate, optical means to project images from opposite sides of the illuminated film upon opposite sides of a film in the positive film gate, and means to ifiillternately expose and obscure the latter 11. In a photographic printer for projecting suitably registered images from a negative film upon opposite sides of a positive naeneae film, in combination, negative and positive film gates arranged to support two independent films, means for illuminating a film in the negative film gate, optical means to project images from opposite sides of a film in the negative film gate upon opposite sides of a film in the positive film gate, and exposure shutters Working on opposite sides of the positive film gate to alternately expose and obscure a film therein.

12. In a photographic printer, in combination negative and positive film gates arranged to support two independent films, means to illuminate both sides of a film in the negative film gate, and optical means for projecting images from opposite sides of the film in the negative film gate upon opposite sides of a film in the positive film gate.

In testimony whereof I hereunto afiix' my signature.

PERCY D. BREWSTER, 

